Method of and apparatus for treating metal



March 2 ,1926, 1,574,823

W. C. KRONQUEST METHOD OF AND APPARATUS FOR TREATING METAL Filed May 27,1925 I I Q n 2 E {M m i R N MU g mi 2 Q i W? EN 5R- 5 r \p I R [Wm 6W0mi N ZZZ following is a specification.

l atented Mar. 2, 1 926. i

1 UNITED STATES PATENT OFFICE.

WILLIAM C. KRONQUEST, OF, CHICAGO, ILLINOIS, ASSIGNOR T0 ACME STEELCOMPANY,

OF CHICAGO, ILLINOIS, A. CORPORATION OF ILLINOIS.

METHOD or an!) ArPAnA'rus son 'rnna'rrno iitn'mn.

' Application filed May 27, 1925. Serial No. 88,148.

To "all whom it may concern: Tension is maintained on the strip throu h-Be it known that 1, WILLIAM C. KnoN- out its length so as to keep it ata definite QUEST, a citizen of the United States, residheight in thetanks, g ing at Ghicago, in the county of Cook and The pickling fluid inthe tank 10 consists State of Illinois, have invented a new andpreferably of a solution of sulphuric acid useful Improvement in Methodsof and Apin water such as is commonly used in pickparatus for TreatingMetal, of which the ling metal. Beneath the metal strlp A in thepickling tank are placed a series of This invention relates to a methodof and plates 24 of lead or other electrical conductapparatus fortreating metal, particularly ing material which will not be acted uponsheet steel strips or the like prior to electi by the acid and these areconnected to the plating, coating or working. c

In the process of cleaning metal with acids, there is a strong tendencyfor it to adsorb and retain gases, especially hydro gen. Such a gas whenpermitted to remain in the metal during the plating operation,

negative pole of a source of current 25, the positive pole beingconnected to the middle rollers 13, 16, 17 and 20L The sulphuric acidsolution acts as a pickling agent, thoroughly cleaning the surface ofthe metal strip A therein. At the same causes blisters to form under theplating. time thestrip itself A serves as the anode It also changes thephysical characteristics and the lead bars as the cathode of an elecofsome metals, as steel, which becomes brittrolytic cell which decreasesthe amount of tie when hydrogen is thus occluded. I I

The primary object of this invention, is to provide a process of andmeans fordecreasing the adsorption of gas at this time by the metal tobe plated or otherwise treated.

Another object is to provide a process for thoroughly cleaning orpicking the, metal. v

These and other objects, which will hereinafter appear are accomplishedby this invention which is fully described in the-followingspecification and shown in the accompanying drawing in which the figureis a diagrammatic vertical section through the pickling andelectro-plating tanks.

The embodiment illustrated comprises a pickling tank 10, a washing tank11 and an electro-plating tank 12 arranged in a convenient series sothat a strip of sheet metal A may be fed continuously through them. Thisstrip A passes over a metal roller 13 which lies outside the picklingtank 10, thence down under the 'rollers 14 and 15 which lie beneath thesurface of the pick ling fluid in the tank 10, thence over rollers 16and 17and then under rollers 18 and 19 which carry the strip beneath thesurface of the washing fluid of the tank 11.

The strip then passes over a roller 20 and into the electro-plating tank12 where it passes under rollers 21 and 22. From this tank. it passesout over a roller 23 and thence to a reel or the like (not shown),

"the metal strips serving as the anode.

lead or other material which are connected to the negative pole of thesource of current 25. The sheet metal plate then passes over a roller 20and into the electro-plating tank 12. It is desired that the metal stripshall remain moist throughout the time it is passing from the picklingtanklO to the washing tank 11 and again from "the washing tank 11 to theelectro-plating tank 12. To prevent drying, particularly after leavingthe washing tanl the solution therein is kept quite cold so as toprevent eva oration during the time the strip is passing rom one tank tothe next. To do this and to dilute the acid which,is being carried in bythe strip A, a constant streamgof cold water is fed through a pipe 27,the level of the water in the tank 11 being kept to the level of theoverflow 28. The pickling solution however may be heated.

The metal strip A isthen electro-plated manner as by means of the metalroller 23 which is connected to the negative side of the generator 29While the anode plates 30 are connected to the positive side of thegenerator.

It will be understood that-the explanation of the action of the hereindescribed process is believed to be the true one but that the inventionis not to be limited thereby. Moreover this process, while primarilyintended to be used preparatory to electroplating, may also be use forpickling metal prior to painting, rolling, stamping or other suhse uentoperations wherein the -preseucc of hydrogen in the metal isobjectionable.

The process illustrated is for a continuous sheet but it is apparentthat it applies to non-continuous sheets and to castings or the like.

While I have shown and described but a single embodiment of thisinvention, it is to be understood that it is capable of manymodifications. Changes therefore in the construction and arrangement maybe made which do not depart from the spirit and scope of the inventionas disclosed in the appended claims.

claim:

1. The method of pickling metal consisting of immersing the metal in asolution ot'acid and water, and passing an electric current through saidmetal while so immersed, the metal forming the anode plate of anelectrolytic cell thereby decreasing the amount of hydrogen adsorbedthereby, the cathode being a material which does not combine chemically.with said acid under ordinary conditions.

2. The method of pickling metal consisting of immersing the metal in asolution of acid and water, and passing an electric current through saidmetal while so immersed, the metal forming the anode plate of anelectrolytic cell thereby decreasing the amount of hydrogenadsorbed'thereby, the cathode plate being lead.

3. The method of electro-plating a continuous strip of metal consistingof passing the metal strip through a cleaning solution, simultaneouslysubstantially preventing the adsorption of hydrogen by said strip,washing said strip, and passingit intothe elec-.

tro-plating tank.

4. The method of electro-plating a continuous strip of metal consistingof passing the metal strip through a cleaning solution, simultaneouslysubstantially preventing the liberation of hydrogen on said strip,washing said strip, and passin ,it into the electro-plating tank whilesaid strip is still wet.

5. The method of electro-platin a continuous strip of metal consisting opassing the metal strip through a cleaning solution, simultaneouslysubstantially preventing the liberation of hydrogen on said strip,washing said strip, and passing it into the electro-plating tank, thewashing solution being cold so as to prevent evaporation before the wetstrip enters the electrolyte of the plating tank.

6. Apparatus for preparing metal for subsequent operations comprising atank containing an acid pickling solution in which the metal isimmersed, and means for passing an electric current through said metalto decrease the adsorption of hydrogen by said metal.

7. Apparatus for preparing metal for subsequent operations comprising atank containing a solution of sulphuric acid in which the metal isimmersed, and means for substantially preventing the adsorption ofhydrogen by said metal.

8. Apparatus for preparing metal for subsequent operations comprising atank containing a solution of sul 'huric acid in which the metal isimmerse means for substantially reventing the liberation of hydrogen ont e surface of said metal, and means for washing said metal.

9. Apparatus for cleaning and electroplating a continuous strip of metalcomprising apickling tank, means therein for substantially preventingthe adsorption of hydrogen by said metal strip which is to be plated,means for washing said strip, and

means for electrolating said strip.

10. Apparatus or cleaning and electroplating a continuous strip of metalcomprising a pickling tank, means therein for substantially preventingliberation of hydrogen on the surface of said metal strip which is to beplated, means for Washing said strip, means for substantially preventingthe liberation, of hydrogen on said strip while being washed, and meansfor electro-plating said strip.

11. Apparatus for preparing metal for subsequent operations comprisinga. tank containing a solutionof sulphuric acid in which the metal isimmersed, an electrical conducting material inactive to sulphuric acidat normal temperatures, and a source of electrical current connected tosaid plate and material so that hydrogen will be liberated on saidmaterial.

WILLIAM C. KRONQUEST.

